<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title></title>
    <script>
    function *show(){
      alert('aaa');

      yield 55;

      alert('bbb');

      return 89;
    }

    let gen=show();

    let res1=gen.next();console.log(res1);    //{value: 55, done: false}

    let res2=gen.next();console.log(res2);    //{value: 89, done: true}
    </script>
  </head>
  <body>

  </body>
</html>
